IBM Plant Codes

List of Known Codes

Content by Tomáš Slavotínek, Tim Clarke, and Christian PL.


IBM plant codes are 2-digit numbers identifying the facility where a given product was manufactured and/or assembled. These codes can be found on many IBM products - most significantly on assembled units and integrated circuits.

Systems and Other Units

Main units, monitors, terminals, storage units, and various other IBM products typically come with a type/serial number sticker. The unique serial number often starts with a 2-digit prefix - the plant code. Something like this:

S/N 55-2Z0R2

Here the "55" indicates that the machine (IBM PS/2 Model 95) was manufactured/assembled in Greenock, UK.

Integrated Circuits

Similar information can be found on many IBM-made integrated circuits. However, our understanding of the used format and values is very limited at the moment. In general, the code consists of an "IBM" prefix, followed by one or two 2-digit plant codes, terminated by an optional "Q", "P", or "PQ" suffix. Here are a few examples:

IBM 53 52Q
IBM 93 14
IBM 9352PQ
IBM 9352
IBM 98

The spacing between the individual sections seems to be greatly inconsistent and most likely can be ignored.

The "IBM" prefix is self-explanatory. Sometimes it appears in form of the striped IBM logo, but often shares a more pedestrian font with the rest of the chip labeling.

It's currently unknown what the "Q"/"PQ" suffix indicates. The most common theory is that it stands for "Qualification" and "Pre-Qualification" respectively. But if that's the case, then IBM shipped an awful amount of pre-qualification IC samples in their products - which seems rather questionable. The rare "P" suffix might stand for "Prototype" (seen on THIS unreleased adapter).

Some chips have a single 2-digit plant number, while others have two 2-digit numbers (4 digits total). The latter variant possibly indicates where the die was fabricated and where the chip was packaged - in cases where the two aren't the same (but it's unknown in what order, if correct at all).

List of Known Codes

Note: Some of the information presented here is currently unconfirmed and may be inaccurate.

00USA generic
02Poughkeepsie, NY, USA[1]
10Rochester, NY, USA[1]
11Lexington, KY, USA[1]
16Sweden (Jarfalla?)[1]
26Austin, TX, USA[1]
273rd party?units
31United Kingdom[1]
35France (Bordeaux?)[1]
43Italy (Vimercate?)[1]
44Santa Palomba, Italy[1]
55Greenock, Scotland, UK[2]
58Amsterdam, Netherlands[1]
65Dublin, Ireland 93b[1]
72Germany or USA?units
77Spain (Valencia?)units
78Guadalajara, Mexico[1]
83Dublin, Ireland 99b[1]
90Wangaratta, Australia[1]
93Canada (Bromont?)IC...[1]
694 (?)United Kingdom


  • [1] IBM typewriter reference (thx Tim Clarke)
  • [2] Empirical evidence (system units of known origins, etc.)


  • Plant codes "53 14" and "93 14" appear on many PowerPC 601(+) CPUs. These chips were produced only at Burlington, VT, USA and East Fishkill, NY, USA. It's however unknown how this maps to the plant codes. The same code combinations can be found on other (CMOS?) chips from the same era.

Content created and/or collected by:
Louis Ohland, Peter Wendt, David Beem, William Walsh, Tatsuo Sunagawa, Jim Shorney, Tim Clarke, Kevin Bowling, Tomáš Slavotínek, and many others.

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Last update: 26 Sep 2022 - Changelog | Legal Info & Contact